JP5590612B2 - COMMUNICATION DEVICE, COMMUNICATION METHOD, AND PROGRAM - Google Patents

Description

  The present invention relates to a communication device, a communication method, and a program for performing multihop communication.

  A CPRI (Common Public Radio Interface) standard interface is employed for connection between a radio equipment and a radio equipment in a base station such as a mobile phone system (for example, see Patent Document 1).

  There is a system in which a wireless device connected to a wireless control device (higher node) via a CPRI standard interface is further connected to another device (lower node) via a CPRI standard interface. In this system, an upper node performs multi-hop communication with a lower node via a wireless device. This multi-hop communication is performed using a clock signal output by the wireless device.

JP 2010-166531 A

  However, when the wireless device cannot output a clock signal due to an abnormality such as a failure, multi-hop communication may be interrupted.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a communication device, a communication method, and a program that can prevent interruption of multi-hop communication as much as possible.

In order to achieve the above object, a communication device according to the first aspect of the present invention provides:
A first communication unit that establishes a first communication link according to the CPRI standard and communicates with an upper node;
A second communication unit for establishing a second communication link according to the CPRI standard and communicating with a lower node;
A clock signal output unit for outputting a clock signal used for communication via the second communication link;
An abnormality detection unit for detecting an output abnormality of the clock signal by the clock signal output unit;
An extraction unit that extracts a clock signal transmitted from the higher order node via the first communication link when an output abnormality is detected by the abnormality detection unit;
When an output abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, the state of the second communication link is limited to a state E or less in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted by the extraction unit, the restriction to state E or less is canceled after a lapse of a certain time after the extraction of the clock signal by the extraction unit, and the clock signal extracted by the extraction unit is used. A communication control unit that communicates with the lower node via the second communication link;
Is provided.
A communication device according to a second aspect of the present invention is
A first communication unit that establishes a first communication link according to the CPRI standard and communicates with an upper node;
A second communication unit for establishing a second communication link according to the CPRI standard and communicating with a lower node;
A clock signal output unit for outputting a clock signal used for communication via the second communication link;
An abnormality detection unit for detecting an output abnormality of the clock signal by the clock signal output unit;
An extraction unit that extracts a clock signal transmitted from the higher order node via the first communication link when an output abnormality is detected by the abnormality detection unit;
When an output abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted by the extraction unit after the restriction to the state E or less is released after a lapse of a certain time after the first communication link becomes the state F in the CPRI standard, the extraction unit extracts the clock signal. A communication control unit that communicates with the lower order node via the second communication link using a clock signal;
Is provided.

A communication method according to the third aspect of the present invention is as follows.
Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device A device communication method comprising:
An abnormality detection step of detecting an output abnormality of the clock signal;
When an output abnormality is detected in the abnormality detection step, an extraction step of extracting a clock signal transmitted from the upper node via the first communication link;
When an output abnormality is detected in the abnormality detection step, if the clock signal is not extracted in the extraction step, the state of the second communication link is limited to a state E or less in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted in the extraction step, the restriction to state E or less is released after a lapse of a certain time after the clock signal is extracted in the extraction step, and the clock signal extracted in the extraction step is used. A communication control step of communicating with the lower node via the second communication link;
Is provided.
A communication method according to the fourth aspect of the present invention is as follows.
Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device A device communication method comprising:
An abnormality detection step of detecting an output abnormality of the clock signal;
When an output abnormality is detected in the abnormality detection step, an extraction step of extracting a clock signal transmitted from the upper node via the first communication link;
When an output abnormality is detected in the abnormality detection step, if a clock signal is not extracted in the extraction step, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted in the extraction step after the restriction to the state E or less is released after a lapse of a certain time after the first communication link becomes the state F in the CPRI standard, the extraction is performed in the extraction step. A communication control step of communicating with the lower order node via the second communication link using a clock signal;
Is provided.

A program according to the fifth aspect of the present invention is:
Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device To the computer that controls the device,
An abnormality detection procedure for detecting an abnormality in the output of the clock signal;
An extraction procedure for extracting a clock signal transmitted from the upper node via the first communication link when an output abnormality is detected in the abnormality detection procedure;
When an output abnormality is detected in the abnormality detection procedure, if a clock signal is not extracted in the extraction procedure, the state of the second communication link is limited to a state E or less in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted in the extraction procedure, the restriction to state E or less is canceled after a lapse of a certain time after the clock signal is extracted in the extraction procedure, and the clock signal extracted in the extraction procedure is used. A communication control procedure for communicating with the subordinate node via the second communication link;
Is executed.
A program according to the sixth aspect of the present invention is
Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device To the computer that controls the device,
An abnormality detection procedure for detecting an abnormality in the output of the clock signal;
An extraction procedure for extracting a clock signal transmitted from the upper node via the first communication link when an output abnormality is detected in the abnormality detection procedure;
When an output abnormality is detected in the abnormality detection procedure, if a clock signal is not extracted in the extraction procedure, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the restriction to state E or less is released after a lapse of a certain time after the first communication link becomes the state F in the CPRI standard, and the clock signal is extracted in the extraction procedure, it is extracted in the extraction procedure. A communication control procedure for communicating with the subordinate node via the second communication link using a clock signal;
Is executed.

  According to the present invention, when detecting an abnormality in the clock signal output unit, the communication device extracts the clock signal transmitted from the upper node, and communicates with the lower node using the extracted clock signal. By doing so, the communication device can communicate with the lower-level node without depending on the state of the clock signal output unit, so that interruption of multi-hop communication can be prevented as much as possible.

2 is a block diagram illustrating a configuration of a base station apparatus according to Embodiment 1. FIG. It is a block diagram which shows the structure of the radio | wireless control apparatus of FIG. It is a block diagram which shows the structure of the radio | wireless apparatus of FIG. FIG. 4A is a diagram illustrating communication between devices when a wireless device outputs a clock signal. FIG. 4B is a diagram illustrating communication between devices when the wireless device does not output a clock signal. It is a flowchart of the selection process of the clock signal by a radio | wireless apparatus. It is a flowchart of the communication control process by a radio | wireless apparatus.

  Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1)
As shown in FIG. 1, the base station device 100 communicates with the mobile station device 4. The mobile station device 100 includes a radio control device 1, a radio device 2, and a radio device 3. Each of these devices has a CPRI standard communication function. The wireless device 2 is connected to the wireless control device 1 (higher-order node) via an optical fiber 202 and can communicate via a CPRI standard interface 200 (hereinafter simply referred to as “CPRI link 200”). The wireless device 2 is connected to the wireless device 3 (lower node) via an optical fiber 302, and can communicate via a CPRI standard interface 300 (hereinafter simply referred to as “CPRI link 300”).

  The CPRI 200 as the first communication link is a communication interface between the wireless device 2 and the wireless control device 1. The CPRI link 200 constitutes a downlink that transmits data from the radio control apparatus 1 to the radio apparatus 2 and an uplink that transmits data from the radio apparatus 2 to the radio control apparatus 1.

  The CPRI 300 as the second communication link is a communication interface between the wireless device 2 and the wireless device 3. The CPRI link 300 constitutes a downlink for transmitting data from the wireless device 2 to the wireless device 3 and an uplink for transmitting data from the wireless device 2 to the wireless control device 1.

  Specifically, the data transmitted / received via the CPRI link 200 and the CPRI link 300 are the Control & Management plane data for control of the wireless device 2 and the wireless device 3 and the User transmitted / received between the mobile station device 4. Plain data (hereinafter, these are simply referred to as “messages”).

  In the CPRI link 200, the wireless control device 1 is a master for the wireless device 2. On the other hand, the wireless device 2 is a slave to the wireless control device 1. The wireless control device 1 transmits a message to the wireless device 2 via the CPRI link 200. The wireless device 2 that has received this message transmits a response message to the wireless control device 1 via the CPRI link 200.

  In the CPRI link 300, the wireless device 2 is a master for the wireless device 3. On the other hand, the wireless device 3 is a slave to the wireless device 2. The wireless device 2 transmits a message to the wireless device 3 via the CPRI link 300. The wireless device 3 that has received the message transmits a response message to the wireless device 2 via the CPRI link 300.

  The wireless control device 1 controls the wireless device 2 by transmitting a message to the wireless device 2. Further, the wireless control device 1 controls the wireless device 3 by transmitting a message to the wireless device 3 via the wireless device 2.

  The CPRI link 200 will be described in further detail. The CPRI link 200 includes a physical layer that is a first layer and a data link layer that is a second layer. In the CPRI link 200, communication functions are sequentially established by executing predetermined processing in each of a plurality of states. The state of the CPRI link 200 includes state A, state B, state C, state D, state E, and state F.

  The state A is a standby state waiting for setting for establishing the CPRI link 200. In state B, the line bit rate of the communication interface is determined, and the master side and the slave side tune the physical layer. In state C, a common protocol for the master side and the slave side is determined. In state D, the message bit rate is determined and the data link layer is established. In state E, the master side and slave side applications are adjusted. In state F, the CPRI link 200 is established and messages can be sent and received. The states of the CPRI link 200 and the CPRI link 300 are managed independently.

  Since the CPRI link 200 and the CPRI link 300 have the same configuration, detailed description of the CPRI link 300 is omitted.

  As illustrated in FIG. 2, the wireless control device 1 includes a signal processing unit 11, a clock signal output unit 12, a storage unit 13, a control unit 14, and an interface unit 15.

  The signal processing unit 11 demodulates, deframes, decodes, etc., the radio signal received via the radio device 2 and the radio device 3. In addition, the signal processing unit 11 performs modulation, framing, encoding, and the like on the baseband signal in order to generate a radio signal transmitted via the radio apparatus 2 and the radio apparatus 3.

  The clock signal output unit 12 outputs a clock signal used for communication with the wireless device 2 via the CPRI link 200. The clock signal output unit 12 outputs the output clock signal to the interface unit 15.

  The storage unit 13 includes, for example, a readable / writable nonvolatile semiconductor memory such as a flash memory. The storage unit 13 stores various programs and data necessary for the operation of the wireless control device 1.

  The control unit 14 includes a CPU (Central Processing Unit, not shown), and the CPU 14 executes various programs stored in the storage unit 13 so that the control unit 14 comprehensively controls each unit of the wireless control device 1. The following processes are executed.

  Further, the control unit 14 generates a message. The control unit 14 outputs the generated message to the interface unit 15.

  The interface unit 15 receives the message output from the signal processing unit 11 and the control unit 14 via the CPRI link 200 established with the wireless device 2 and the clock signal output from the clock signal output unit 12. Send to. The interface unit 15 outputs the message transmitted from the wireless device 2 to the control unit 14 and the signal processing unit 11.

  Next, the configuration of the wireless device 2 will be described. As illustrated in FIG. 3, the wireless device 2 includes a communication unit 20, a storage unit 21, a clock signal output unit 22, a control unit 23, and an interface unit 24.

  The communication unit 20 is connected to the antenna 201. The communication unit 20 converts the baseband signal output from the interface unit 24 into a radio signal and transmits the radio signal to the mobile station device 4 via the antenna 201. Further, the communication unit 20 converts the radio signal transmitted by the mobile station device 4 via the antenna 201 into a baseband signal and outputs the baseband signal to the interface unit 24.

  The storage unit 21 includes a readable / writable nonvolatile semiconductor memory such as a flash memory. The storage unit 21 stores various programs and data necessary for the operation of the wireless device 2.

  The clock signal output unit 22 generates and outputs a clock signal used for communication with the wireless device 3 via the CPRI link 300. The clock signal output unit 22 outputs the output clock signal to the control unit 23 and the interface unit 24.

  The control unit 23 includes a CPU (Central Processing Unit, not shown), an abnormality detection unit 25, an extraction unit 26, and a communication control unit 27. The CPU executes various programs stored in the storage unit 21 to realize functions of the abnormality detection unit 25, the extraction unit 26, the communication control unit 27, and the like, and the control unit 23 controls each unit of the wireless device 2. In addition to overall control, the following processes are executed.

  Further, the control unit 23 generates a message. The control unit 23 outputs the generated message to the interface unit 24.

  The abnormality detection unit 25 detects an output abnormality of the clock signal by the clock signal output unit 22.

  The extraction unit 26 extracts a clock signal transmitted from the radio network controller 1 via the CPRI link 200 when an output abnormality is detected by the abnormality detection unit 25.

  When the abnormality detection unit 25 detects an output abnormality, the communication control unit 27 transmits / receives a message to / from the wireless device 3 via the CPRI link 300 using the clock signal extracted by the extraction unit 26.

  The interface unit 24 includes a slave interface unit 24a and a master interface unit 24b. The slave interface unit 24a functions as a first communication unit, and receives a clock signal, a message, and the like transmitted from the radio network controller 1. Further, the slave interface unit 24 a transmits a response message to the message transmitted from the wireless control device 1 to the wireless control device 1.

  The wireless device 2 includes a PLL (Phase Locked Loop) circuit (not shown). The wireless device 2 establishes communication via the CPRI link 200 by synchronizing the phase of the clock signal transmitted from the wireless control device 1 and the phase of the operation clock signal output from the PLL circuit (PLL lock). As a result, transmission / reception of messages between the wireless control device 1 and the wireless device 2 becomes possible.

  The master interface unit 24b functions as a second communication unit and wirelessly transmits the clock signal and message transmitted from the wireless control device 1, the clock signal output from the clock signal output unit 22, and the message output from the control unit 23. Transmit to device 3. The master interface unit 24 b receives a response message transmitted to the wireless device 3.

  In the wireless device 3, the clock signal transmitted from the wireless device 2 is PLL-locked to establish communication via the CPRI link 300. As a result, transmission / reception of messages between the wireless device 2 and the wireless device 3 becomes possible.

  The configuration of the wireless device 3 is the same as that of the wireless device 2. However, in the present embodiment, since the wireless device 3 does not operate as a master, the interface unit 24 may not include the master interface unit 24b.

  Here, multi-hop communication in the wireless control device 1, the wireless device 2, and the wireless device 3 will be described.

  As illustrated in FIG. 4A, the wireless device 2 transmits and receives messages to and from the wireless control device 1 using the clock signal transmitted from the wireless control device 1. The wireless device 2 transmits and receives messages to and from the wireless device 3 using the clock signal output from the clock signal output unit 22.

  However, for example, when the clock signal output unit 22 cannot output a clock signal due to an abnormality such as a failure, the wireless device 2 wirelessly uses the clock signal extracted by the extraction unit 26 as shown in FIG. Messages are transmitted to and received from the device 3.

  Next, the flow of the clock signal selection process in the first embodiment will be described with reference to FIG.

  As a premise, it is assumed that the CPRI link 200 and the CPRI link 300 are both in the state F, and that the wireless control device 1 and the wireless devices 2 and 3 can transmit and receive messages.

  If no output abnormality is detected by the abnormality detection unit 25 (step S1; No), the communication control unit 27 selects the clock signal output from the clock signal output unit 22 as a clock signal used for communication via the CPRI link 300. (Step S2). The communication control unit 27 transmits a message to the wireless device 3 using the clock signal output from the clock signal output unit 22 (step S5).

  On the other hand, when the output abnormality is detected by the abnormality detection unit 25 (step S1; Yes), the extraction unit 26 starts extracting the clock signal transmitted from the wireless control device 1 (step S3). Then, the communication control unit 27 selects the extracted clock signal as a clock signal used for communication via the CPRI link 300 (step S4). The communication control unit 27 transmits a message to the wireless device 3 using the extracted clock signal (step S5).

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described.

  As described above, when an output abnormality is detected by the abnormality detection unit 25, a message is transmitted to the wireless device 3 using the clock signal extracted by the extraction unit 26. Thereby, the multihop communication in the wireless control device 1, the wireless device 2, and the wireless device 3 is continued. However, if the wireless control device 1 is reset in this state, transmission of the clock signal from the wireless control device 1 is stopped, so that the extraction unit 26 cannot extract the clock signal. Then, the state of the CPRI link 300 is changed from B → C → D → E → F → B → C → D → E → F → B until the clock signal is extracted by the extraction unit 26 and the PLL lock is performed by the wireless device 3. .., And the state F in which the message can be transmitted and received is not maintained for a certain time. For this reason, the response message to the message transmitted to the wireless device 3 by the wireless device 2 does not reach the wireless device 2, and the wireless device 2 repeatedly transmits the message to the wireless device 3.

  If this state continues, the wireless device 2 forcibly stops the message transmission because the response message cannot be received even if the message is repeatedly transmitted. When message transmission is forcibly stopped, message transmission / reception between the wireless device 2 and the wireless device 3 cannot be recovered until the wireless device 2 is reset.

  In order to prevent this forcible stop, the communication control unit 27 temporarily communicates with the wireless device 3 via the CPRI link 300 when an abnormality is detected by the abnormality detection unit 25 and a clock signal is not extracted by the extraction unit 26. Stop. Then, when the clock signal is extracted by the extraction unit 26, the communication control unit 27 communicates with the wireless device 3 via the CPRI link 300 using the clock signal extracted by the extraction unit 26.

  More specifically, when an abnormality is detected by the abnormality detection unit 25, the communication control unit 27 restricts the state of the CPRI link 300 to the state E or less unless the extraction unit 26 extracts a clock signal. And the communication control part 27 cancels | releases the restriction | limiting to state E or less after progress for a fixed time after a clock signal is extracted by the extraction part 26. FIG.

  This is because the CPRI link 200 is established when the clock signal transmitted from the wireless control device 1 is PLL-locked by the wireless device 2 after a predetermined time has passed, and the clock signal transmitted from the wireless control device 1 is It is because it is thought that it is receiving.

  In this case, the communication control unit 27 may release the restriction to the state E or lower after a predetermined time has elapsed after the state of the CPRI link 200 becomes the state F.

  Next, the flow of communication control processing will be described with reference to FIG.

  If no abnormality is detected by the abnormality detection unit 25 (step S11; No), the communication control unit 27 selects the clock signal output by the clock signal output unit 22 as a clock signal used for communication via the CPRI link 300 ( Step S12). The communication control unit 27 transmits a message to the wireless device 3 using the clock signal output by the clock signal output unit 22 (step S19).

  When an abnormality is detected by the abnormality detection unit 25 (step S11; Yes), the extraction unit 26 starts extracting a clock signal transmitted from the wireless control device 1 (step S13). If the clock signal is extracted by the extraction unit 26 (step S14; Yes), the communication control unit 27 selects the extracted clock signal (step S18). And the communication control part 27 transmits a message to the radio | wireless apparatus 3 using the extracted clock signal (step S19).

  On the other hand, if the clock signal is not extracted by the extraction unit 26 (step S14; No), the communication control unit 27 restricts the state of the CPRI link 300 to the state E or less (step S15).

  The communication control unit 27 waits until a predetermined time elapses after the extraction unit 26 extracts the clock signal (step S16; No). When a predetermined time has elapsed after the clock signal is extracted by the extraction unit 26 (step S16; Yes), the communication control unit 27 releases the restriction to the state E or less (step S17).

  Next, the communication control unit 27 selects the clock signal extracted by the extraction unit 26 (step S18). And the communication control part 27 transmits a message to the radio | wireless apparatus 3 using the extracted clock signal (step S19).

  As described above, according to each of the above embodiments, when the wireless device 2 detects an abnormality in the clock signal output unit 22, the wireless device 2 extracts the clock signal transmitted from the wireless control device 1, and extracts the extracted clock signal. To send a message to the wireless device 3. By doing so, since the wireless device 2 can transmit a message to the wireless device 3 without depending on the state of the clock signal output unit 22, it is possible to prevent interruption of multi-hop communication as much as possible.

  Further, according to the second embodiment, when the clock signal is not extracted, the state of the CPRI link 300 is limited to the state E or less, and when the clock signal is extracted, the restriction to the state E or less is released. By doing so, the forced stop of message transmission due to the wireless device B being unable to respond is avoided, and when the clock signal is extracted, the message transmission is resumed. For this reason, even if the wireless control device 1 is reset while the clock signal output unit 22 is abnormal, it is possible to prevent interruption of multi-hop communication as much as possible.

  In each of the above embodiments, the wireless control device 1, the wireless device 2, and the wireless device 3 are established according to the CPRI standard. Since the CPRI standard is a standardized protocol interface, it is possible to interconnect devices provided by different operators.

  In each of the above embodiments, two wireless devices are connected to the wireless control device 1, but three or more wireless devices may be connected. Further, in each of the above embodiments, the radio apparatus is connected to the radio network controller 1 in series (chain topology), but the radio apparatuses 2 and later connected to the radio network controller 1 are distributed in parallel and connected to a plurality of radio apparatuses. (Tree topology) may be used, and a terminal of a wireless device connected in series may be connected to the wireless control device 1 (ring topology).

  In the present embodiment, the case where the wireless control device 1 is reset is exemplified. However, for example, the wireless control device 1, the wireless device 2, and the wireless device 3 are in a state where the clock signal output unit 22 of the wireless device 2 is abnormal. Even if the communication control unit 28 is activated, the communication control unit 28 restricts the state of the CPRI link 300 to the state E or lower until a predetermined time has elapsed after the clock signal is extracted, so that the transmission of the message is not forcibly stopped. The device 2 can send and receive messages to and from the wireless device 3 using the extracted clock signal.

  In the present embodiment, the predetermined time that is a condition for the communication control unit 27 to release the restriction to the state E or lower may be determined by the operator according to the base station device 100. .

  In the above embodiment, the program to be executed is stored in a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versatile Disk), or an MO (Magneto Optical Disk). Then, the base station apparatus 100 that executes the above-described processing may be configured by distributing and installing the program.

  Further, the program may be stored in a disk device or the like of a predetermined server device on a communication network such as the Internet, and may be downloaded, for example, superimposed on a carrier wave.

  In addition, when the above functions are realized by sharing an OS (Operating System) or when the above functions are realized by cooperation between the OS and an application, only the part other than the OS is stored in a medium and distributed. It may also be downloaded.

  In addition, this invention is not limited by the said embodiment and drawing. It goes without saying that the embodiments and the drawings can be modified without changing the gist of the present invention.

(Supplementary Note 1) A first communication unit that establishes a first communication link and communicates with an upper node;
A second communication unit for establishing a second communication link and communicating with a lower node;
A clock signal output unit for outputting a clock signal used for communication via the second communication link;
An abnormality detection unit for detecting an output abnormality of the clock signal by the clock signal output unit;
An extraction unit that extracts a clock signal transmitted from the higher order node via the first communication link when an output abnormality is detected by the abnormality detection unit;
A communication control unit that communicates with the lower-level node via the second communication link using the clock signal extracted by the extraction unit when an output abnormality is detected by the abnormality detection unit;
A communication device comprising:

(Appendix 2) The communication control unit
When an abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, communication with the lower-order node via the second communication link is temporarily stopped.
If the clock signal is extracted by the extraction unit, the clock signal extracted by the extraction unit is used to communicate with the lower-order node via the second communication link.
The communication apparatus according to supplementary note 1, wherein:

(Appendix 3) The first communication link and the second communication link are:
Each established according to CPRI standards,
The communication control unit
When an abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, the state of the second communication link is limited to a state E or lower in the CPRI standard, and the clock signal is generated by the extraction unit. The restriction to state E or lower is released after a certain time has passed since extraction.
The communication apparatus according to Supplementary Note 2, wherein

(Appendix 4) The first communication link and the second communication link are:
Each established according to CPRI standards,
The communication control unit
When an abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the first communication link is The restriction to state E or less is released after a lapse of a certain time after becoming state F in the CPRI standard.
The communication apparatus according to Supplementary Note 2, wherein

(Additional remark 5) The communication method of the communication apparatus which establishes a 1st communication link and communicates with a high-order node, and establishes a 2nd communication link and communicates with a low-order node using the clock signal output within an own machine Because
An abnormality detection step of detecting an output abnormality of the clock signal;
When an output abnormality is detected in the abnormality detection step, an extraction step of extracting a clock signal transmitted from the upper node via the first communication link;
A communication control step of communicating with the lower node via the second communication link using the clock signal extracted in the extraction step when an output abnormality is detected in the abnormality detection step;
A communication method comprising:

(Supplementary Note 6) The first communication link is established to communicate with the upper node, and the second communication link is established to control the communication device that communicates with the lower node using the clock signal output within the own device. On the computer,
An abnormality detection procedure for detecting an abnormality in the output of the clock signal;
An extraction procedure for extracting a clock signal transmitted from the upper node via the first communication link when an output abnormality is detected in the abnormality detection procedure;
A communication control procedure for communicating with the lower-order node via the second communication link using the clock signal extracted in the extraction procedure when an output abnormality is detected in the abnormality detection procedure;
A program for running

DESCRIPTION OF SYMBOLS 1 Radio control apparatus 2, 3 Radio apparatus 4 Mobile station apparatus 11 Signal processing part 12, 22 Clock signal output part 13, 21 Storage part 14, 23 Control part 15, 24 Interface part 20 Communication part 24a Slave interface part 24b Master * Interface unit 25 Anomaly detection unit 26 Extraction unit 27 Communication control unit 100 Base station device 200, 300 CPRI link 201, 301 Antenna 202, 302 Optical fiber

Claims (6)

A first communication unit that establishes a first communication link according to the CPRI standard and communicates with an upper node;
A second communication unit for establishing a second communication link according to the CPRI standard and communicating with a lower node;
A clock signal output unit for outputting a clock signal used for communication via the second communication link;
An abnormality detection unit for detecting an output abnormality of the clock signal by the clock signal output unit;
An extraction unit that extracts a clock signal transmitted from the higher order node via the first communication link when an output abnormality is detected by the abnormality detection unit;
When an output abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, the state of the second communication link is limited to a state E or less in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted by the extraction unit, the restriction to state E or less is canceled after a lapse of a certain time after the extraction of the clock signal by the extraction unit, and the clock signal extracted by the extraction unit is used. A communication control unit that communicates with the lower node via the second communication link;
A communication device comprising: A first communication unit that establishes a first communication link according to the CPRI standard and communicates with an upper node;
A second communication unit for establishing a second communication link according to the CPRI standard and communicating with a lower node;
A clock signal output unit for outputting a clock signal used for communication via the second communication link;
An abnormality detection unit for detecting an output abnormality of the clock signal by the clock signal output unit;
An extraction unit that extracts a clock signal transmitted from the higher order node via the first communication link when an output abnormality is detected by the abnormality detection unit;
When an output abnormality is detected by the abnormality detection unit, if the clock signal is not extracted by the extraction unit, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
The first communication link is to cancel the limitation since the state F to the following state E after a predetermined time has elapsed in the CPRI standard, the clock signal by the extracting unit when it is extracted, extracted by the extraction unit A communication control unit that communicates with the lower order node via the second communication link using a clock signal;
A communication device comprising: Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device A device communication method comprising:
An abnormality detection step of detecting an output abnormality of the clock signal;
When an output abnormality is detected in the abnormality detection step, an extraction step of extracting a clock signal transmitted from the upper node via the first communication link;
When an output abnormality is detected in the abnormality detection step, if the clock signal is not extracted in the extraction step, the state of the second communication link is limited to a state E or less in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted in the extraction step, the restriction to state E or less is released after a lapse of a certain time after the clock signal is extracted in the extraction step, and the clock signal extracted in the extraction step is used. A communication control step of communicating with the lower node via the second communication link;
A communication method comprising: Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device A device communication method comprising:
An abnormality detection step of detecting an output abnormality of the clock signal;
When an output abnormality is detected in the abnormality detection step, an extraction step of extracting a clock signal transmitted from the upper node via the first communication link;
When an output abnormality is detected in the abnormality detection step, if a clock signal is not extracted in the extraction step, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted in the extraction step after the restriction to the state E or less is released after a lapse of a certain time after the first communication link becomes the state F in the CPRI standard, the extraction is performed in the extraction step. A communication control step of communicating with the lower order node via the second communication link using a clock signal;
A communication method comprising: Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device To the computer that controls the device,
An abnormality detection procedure for detecting an abnormality in the output of the clock signal;
An extraction procedure for extracting a clock signal transmitted from the upper node via the first communication link when an output abnormality is detected in the abnormality detection procedure;
When an output abnormality is detected in the abnormality detection procedure, if a clock signal is not extracted in the extraction procedure, the state of the second communication link is limited to a state E or less in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the clock signal is extracted in the extraction procedure, the restriction to state E or less is canceled after a lapse of a certain time after the clock signal is extracted in the extraction procedure, and the clock signal extracted in the extraction procedure is used. A communication control procedure for communicating with the subordinate node via the second communication link;
A program for running Communication that establishes the first communication link according to the CPRI standard and communicates with the upper node, and establishes the second communication link according to the CPRI standard and communicates with the lower node using the clock signal output in the own device To the computer that controls the device,
An abnormality detection procedure for detecting an abnormality in the output of the clock signal;
An extraction procedure for extracting a clock signal transmitted from the upper node via the first communication link when an output abnormality is detected in the abnormality detection procedure;
When an output abnormality is detected in the abnormality detection procedure, if a clock signal is not extracted in the extraction procedure, the state of the second communication link is controlled to be equal to or lower than the state E in the CPRI standard, and the second communication Temporarily suspends communication with the subordinate node via the link;
If the restriction to state E or less is released after a lapse of a certain time after the first communication link becomes the state F in the CPRI standard, and the clock signal is extracted in the extraction procedure, it is extracted in the extraction procedure. A communication control procedure for communicating with the subordinate node via the second communication link using a clock signal;
A program for running

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